Although great advance in the treatment of commonly seen cancers has been achieved by combined use of chemotherapy, surgery, and radiotherapy, cancer therapy still faces many challenges in early diagnosis, metastasis, drug resistance, and notorious toxicity of therapeutic agents to normal cells.
Combining anticancer agents with different mechanisms is a common strategy to improve overall efficacy; the combined use of immunotherapy and chemotherapy is one example. Nevertheless, all the agents used themselves are toxic and incur drug resistance; gemcitabine is a good example.
The medicinal herbs called Qi-tonics in Chinese medicines, like ginseng, are also used in the fight against cancers as a popular option of alternative and complementary therapy. These herbal medicines are traditionally used in the form of decoction and are usually rich in polysaccharides. Many of these polysaccharides have been shown to enhance immune system and to suppress tumor growth in various animal models.
Chinese Medicine has a golden therapy strategy: the combined use of tonifying medicines and those having dispelling function. This strategy may fit cancer therapy right: not only to kill the cancer cells, but also to strengthen the body's vital energy (healthy Qi) and restore proper and healthy cell growth. A good example is Shen Qi Fu Zheng Injection (SQFZ Injection) from Livzon Group, which synergy with chemotherapy in cancer clinic has been proved in China and therefore brought a big gross profit of HK$0.5 billion in the past half year. However, this product is facing severe technical challenge like other Chinese herbal injections, because the Chinese Government has increased the requirements of safety and quality control for this special kind of medicinal preparation.
As illustrated in FIG. 1, SQFZ Injection is derived from the water extract of Radix Astragali and Radix Codonopsis after removal of precipitate in 80% ethanol. On the other hand, the removed precipitate, also called production waste, is the typical crude polysaccharide fraction, which shares the same production protocol.
Modern scientific studies have demonstrated that Astragalus polysaccharides exhibit immuno-enhancing effects in vitro and in vivo. Chinese patent application CN1985877A discloses a composition containing Radix Astragali which strengthens immunity, prevents or treats respiratory tract infection, allergic rhinitis, damage of liver caused by glycogen reduction or antitumor medicine, viral hepatitis, regulates blood viscosity and reduces blood fat.
Combined use of Radix Astragali with other herbs has been reported. China patent CN1059800C discloses an injectable composition containing ginseng and Radix Astragali for treatment of immunodeficiency and immune disorder-related diseases. Chinese patent CN1290512C discloses a composition containing ginseng polysaccharide and Astragalus polysaccharide as an injectable formulation for treatment of neoplastic diseases. US patent application 2006/0110473 discloses a composition containing Radix Codonopsis and Radix Astragali for preparation of an immuno-regulator and medicaments for the treatment of ischemic heart diseases and acute lung injury. Chinese patent CN1895337B discloses a composition containing Radix Codonopsis and Radix Astragali for prolonging mortality and improving quality of life in patients of latter-phase cancer, and its preparation into injections, capsules and tablets.
However, knowledge about the chemistry of Astragalus polysaccharides is still limited. It is hard to identify if the same sample was studied in different laboratories and it is also hard to compare their bioactivities.
Therefore, the present invention provides a pharmaceutical composition for modulating immune system comprising at least one polysaccharide extracted from Radix Astragali, Radix Codonopsis, Ganoderma sinense, or mixtures thereof. While common extraction methods stated in the abovementioned prior art discard the ethanol precipitate as production waste, the present invention provides a process for extracting the polysaccharides from the production waste. Also provided is a method of modulating immune system by applying said pharmaceutical composition and a method of preventing and/or pretreating and/or treating cancer which comprises applying said pharmaceutical composition before/during chemotherapy.
Citation or identification of any reference in this section or any other section of this application shall not be construed as an admission that such reference is available as prior art for the present application.